Hydraulic jack



2 Sheets-Sheet v1 HYDRAULIC JACK M, w. HUMPHREYS Oct. 12, 1948.

Filed Aug. 22, 1946 v' 52 47 45 BY H62 M' ATTOR/YE Y Oct. 12, 1948. M. w. HUMPHREYS HYDRAULIC JACK 2 sheets-sheet 2 n v Filed Aug. 22, 194e INVENToR. A

MHz/0N M/./UMPHEE Ys Iulrnlm F Patented Oct. 12, l1948 HYDRAULIC JACK Marion W. Humphreys, Euclid, Ohio, assigner to Euclid Production Development Corp., Euclid, Ohio, a corporation i' Ohio Application August 22, 1946, Serial No. 692,205

1 Claim.

The present invention relates to hydraulic jacks, particularly automobile jacks, and to hydraulic pumps especially adapted for use in hydraulic jacks and the like.

One of the principal objects of the invention is the provision of a novel and improved hydraulic jack comprising a simple and inexpensive pump for supplying the pressure liquid, and readily operable means for permitting the return of the liquid from the lifting cylinder or motor to the liquid reservoir.

Another object of the invention is the provision of a jack of the character referred to, which jack is simple in construction, self-contained, will not leak liquid, and has only one manually operable member selectively movable for raising and lowering the jack.

Another object of the invention is the provision of a novel and improved liquid pump of the reciprocating piston type especially adapted for use in jacks and the like and including byI pass means selectively operable by movement of the piston actuating means for permitting the return of liquid from the lifting cylinder or motor to the reservoir.

The invention resides in certain constructions and combinations and arrangements of parts and further objects and advantages will be apparent to those skilled in the art to which the invention relates from the following description of the preferred embodiment described with reference to the accompanying drawings forming a part oi' this specicaton in which similar reference characters designate corresponding parts, and in which Fig. 1 is a perspective View of an automobile jack embodying the present invention;

Fig. 2 is an enlarged Vertical sectional view through the jack approximately on the center line of the pump and lines 2-2 of Figs. 3 and 4;

Fig. 3 is a detached plan view of the piston as shown in Fig. 2;

Fig. 4 is a sectional View approximately on the line 4-4 of Fig. 2;

Fig. 5 is a sectional vieW similar to Fig. 4 but showing the parts in a diiierent operating position;

Fig. 6 is a fragmentary sectional View approximately on the line 6 5 of Fig. 7 and similar to a part of Fig. 2 but showing the pump piston in a different operating position;

Fig. 7 is a sectional view approximately on the line 1-1 of Fig. 6; and

Fig. 8 -is a fragmentary sectional View similar` 2 to a part 4of Fig. 2 but showing a modified construction.

Although the invention is applicable to devices of different character and may be embodied in various structures, it is particularly applicable to automobile jacks and is herein shown and dscribed as embodied in a manually operable hydraulic automobile jack of specific construction.

Briefly described, the jack shown in the drawings comprises a tubular-like lifting assembly A closed at its upper end and slidably supported for vertical movement upon the upper tubular part of a column-like base member or assembly B also closed at its upper end, the lower part of which is bell-shaped and forms a reservoir for oil or other suitable liquid. The lifting assembly A is raised and lowered upon its supporting column-like base B by the admission and exhaust of pressure liquid to and from the interior of the lifting assembly A about the supporting column B. Pressure iluid is supplied to the interior of the assembly A above the top of the base B by a manually operable pump C located in the base B. The pump C also includes means for controlling the escape of iiuid from the interior of the lifting assembly to lower the jack.

The lifting assembly A comprises a tubular member I@ closed at its upper end by a cupshaped cap Il, the downwardly extending flange of which surrounds and has threaded engagement with the upper end of the tube lo. Packing i2 interposed between the upper end of the tube il) and the interior of the cap il prevents the leakage of any liquid through the threaded connection between the tube is and the cap il. The lower end of the tube i@ is provided with a liange ring i3, the upwardly extending flange of which surrounds and is threaded upon the lower end of the tube til. The interior of the ring I3 below the tube lli slides upon a tubular member M forming a part of the supporting column B and is provided with an internal groove for the reception of an O-ring type packing it, which packing ring seals or closes the lower end of a chamber l1 intermediate the tubular members ID, I4.

In addition to the vertically positioned tubular member I4, the supporting column for the lifting assembly A comprises a plug-like member IS-threaded into' the upper end of the vtube i4 and provided with an annular external ange, the lower side of which engages the upper end of the tube i4. The external flange on the member I8 forms with the interior of the tube I0 of ythe lifting assembly A a sliding lit and is provided with an external groove Within which a packing or seal i9 is positioned. The seal shown is similar to the seal i3 previously referred to and closes the upper end of the chamber l1.

The lower end of the tubular member I4 is threaded into an upwardly extending flange 2l) of the bell-shaped member 2l of the base B and the sihoulderformecl thereby is Vadapted to be engaged by the lower side 4of the member I3 to form -a lower stop for the lifting assembly A. The bell-'shaped member 2l is provided with an external ilange 22 and the bottom is Iclosed by ,a plate 23 xedly secured thereto in Iany convention-al manner. As shown,.the :plate v.23'has:a.'an inwardly extending flange 2li which overrides the flange 2-2 of the bell-shaped member. Pressure fluid is supplied to and exhausted .from-:the interior of the lifting assembly A above the supporting column B, which chamber' is designated herein by the reference lcharacter 25 and is in eiect 'the :power cylinder, :by ragpipemrptube 26, the upper end of which extends into and'fcommunicates with a counterbored1aperture'i2l vthrough thecenter of the plug i. The :pipe 22E is .'xedly secured lwithin the `lovver end of'theaperturei-2l7 by a suitable itting28. The lower-end `of the pipe 25 is connected in a similar bore 3i) in the cylinder`3l of the pump C by a ttingSZsimilar to the tting 28.

'In the embodiment shown, the pump C comprises the one-piece `cylinder `memberfl, "previously referred to, having a cylindrical aperture or ibore 33, Vthe'left-hand closed'end Aof'wifi-encon- `stitutes the cylinder chamber of the pump. 'LThe right-hand end of the cylinder member 3i,-Which is threaded, is rof reduced diameter and lprojects outwardly through a suitable aperture in the vbell-shaped base mem-ber 2l, vto Which't is detachably secured by a1nut`34 ythreaded upon" the outer end.V A Apacking Washer 35 interposed nibo-- tween the yshoulder formed by the reduced-endof the cylinder member 3i and the inner vside of the bell-shaped member 2| prevents rthe leakage of liquid around the cylinder member. The cylinder is in effect a part of thevbase member or assembly B andras an alternative construction, the tubular part I4, the bell-shaped part 21, the bottom member 23, and the ypump'cylirider 3i may be formed in one piece.

Thepiston d of the pump C is vformed rof a solid, cylindrical'member located in the outerA end of the aperture 33-within whichit lis bothrotatable and reciproca-ble. The piston is adapted to be kmanually rotated by a hand crank di detachably connected thereto by 4a ysocket yl2 :having apertures 180 apart adapted to receive opposite ends of a pin 43 projecting from andxedly secured within `a transverse aperture-adjacent to the outer end ofthe piston 4'0. vThe Vpiston 4'0 is reciprocated within the vcylinder member 31 upon rotation of the piston `by a roller L44 rotatably supported on the inner end of 'a' member rlxedly secured Within a radial aperture in the;cylin der member 3|, which roller 44 engages Awithin a continuous, inclined cam groove 4S -in 'the piston .139. A pair of seals 41, 38 similar `to the seal $9, previously referred to and located within'suitable grooves at opposite Vsides of the -cam groove 46, prevent the escape of vliquid aboutthe piston.

The valving for the fluid pressure pump C comprises in addition to `the aperture or port 3B, previously referred to,a radial aperture or-'p-ortf' in the `cylinder member 3! oppositeto-the aperture 33 and communieating `withfthe liquid reserthe piston 40 is fiattened on one side to provide an end portion l, semi-circular in lcross-section and of sufcient length that it always covers one or both of the ports 30, 50 as the piston reciprocates through its normal predetermined stroke effected .by the roller 4'4 in cooperation with the cam groove 4E. The high and low parts of the :cam groovelie in theplane of the fiat surface Aof lthe portion VZ5l of the-'2piston,-vvithl Ythe result that as the piston 'is rotated it reaches the oppo- .site ends of its `strolre as the one port opens and .the other closes. The pump is reversible and can be used to pump the lifting assembly A both up -.andrdown; however,v it is normally intended to pump=-pressure uid into the cham-ber 25, other means ihereinaifterbeing provided for permitting V.tl'iereturn ofliquid to the reservoir for the purpose of lowering the lifting assembly A or jack.

'Whenlerotated Ifrom the position shown in Figs.

2 and 4, with both ports 30, 50 closed, in the direction :indicatedi'by the arrow leEigs. Lincr 5,

4initial movement `of the piston f4!) :opens itheport 33. :The eport i311 :remains'z open'-,l to `the f chamber 33 and as the rotation #of :the :piston@continues the pistongfmoves toward the @bottom .of thee-chambera'A forcing .the liquid :therein ithrough'rthezpurt 3o ,and the; conduiti :intothe chamb'en-fraising the vlifting-assembly A. "When the pistonfh-as been rotated i802 seel Rigid-.the iport; 30;isaagainrclosed 'zby the'xportionslzofzithe piston, fthe iport having closed shortly before reaching thel'ilsposition. Continued: rotation .fof the ip'iston .opensxthegntake port :50 and'Y causes the pistonfto move toward the position i shown in .'Eig. L2 iwhich .ldrawslziluid :into-the chamber 33. iih'eni.th'eupi-ston reaches :the-position shown in "Fig-4, the :cycleoffroperation is completed.

vrAs `previously lstated, A:the epistonsmayvrotatecl Vin fthe opposite directionV to 'loweritheijackyfhowever, 'the'i liquid -Iin :.'the chamber :1125* `is::preferably allowed v'tolr'eturn toi-the reservoir in tl'iesbasesofV the jack ibyoconnectingi'fthe rports'fl, 250G/through .an aperturell in the fpiston 140 :adjacentzatcifbut spaced-'slightly to -thefreair .offthe eend 51|, awhich aperture is adapted to be movedin'line .vviththe 'portsllf- 58' 'by pushing the :pistonfforwarditolthe .face` of :thezipiston fcauses .theif'chamber stosbe Y :connectedfwitl-rthe port- ;51! rat v:the .timethespiston fis :pushed gforwa-rd into .'theoositonrshown in Fig. 6, whereby pressure Vis preventedfromlbuilding lup in frontoffthe piston. Pressurenwithin `the chamber 33 normally maintains ther fr,ontor lefthand -Wall of the ,-camgroove AS- .ini engagement with .the roller land preventsthe Arecess Ain. the rear or right-hand wall of the cam groovelhtom entering ,intothe normal operation of the pump.

'The Y pressure fluids reservoir :Within the'ibase assembly B, includingjthetubular'member'llL is preferably only'partially full of `'liquidand is of a sufiicient size that itcambel sealed'from1fthe outside atmosphere. ePrefera'bly, the volume thereof can be increased fby-forming one'or more voir in the 'Jb-ase 13. The inner or leftehand end A.of f75 radial apertures :;55 an feheesidesilofmeV tblar member I4 adjacent to the top, thus making the chamber I'I intermediate the outer and inner tubular members I and I4 a part of the reservoir. If the holes 55 in the tubular member I4 are dispensed with, the seal I6 serves no particular function and can be omitted. In this event, the ring member I3 can also be omitted and the lower end of the tube I@ drawn in to engage the eX- terior of the tube I4 in a manner similar to that shown at 5B in the alternative construction shown in Fig. 8 wherein the duplicate parts are designated by the same reference characters and the corresponding parts by the same reference characters with a prime mark aixed thereto.

As a further alternative construction, the upper part of the liquid reservoir in the base assembly may be automatically opened to atmosphere and closed as the lifting assembly is raised and lowered. As shown in Fig. 8, this may be accomplished by a conduit 99 in the member I8 corresponding to the member I8 of the embodiment shown in Figs. 1 to 7, the upper end of which conduit opens into an annular groove 6I and is normally closed by an O-ring type packing or seal located in the groove 6I.. The groove 6I is in the circumference of the member I8', is Wider than the O-ring, and as the lifting assembly A is raised, the engagement between the O-ring and the interior of -the tubular member I0 rolls the O-ring away from the end of the conduit 60, thus opening the liquid reservoir to atmosphere through the chamber I1 intermediate the tubular members I0', I4' and the clearance between the lower end of the member I0 and the vtube I4. As the lifting assembly A is lowered, the O-ring is returned to the position shown and the conduit 60 sealed to prevent the escape or liquid therethrough when the jack is laid in a horizontal position. As the lifting assembly A' is being lowered, an operation that normally takes place with the jack in its upright or vertical position, any appreciable pressure Within the liquid reservoir will relieve itself by temporarily lifting the O-ring away from the end of the conduit 60.

The jack can .be placed under the object to be raised with the upper end of the lifting assembly A in position to engage the object or the lifting assembly can include other means for engaging the object to be raised. The lifting assembly preferably includes vertically adjustable means for engaging underneath the object to be raised, thus better adapting the jack for lifting articles of different height from a given surface. This is particularly advantageous in the case of an automobile jack because the axle of the automobile or other part to be engaged by the lifting assembly will be at different heights above the ground for different automobiles, etc. In the embodiment shown, the lifting assembly A includes a member E comprising a plurality of plate-like members 62 loosely connected together by a rivet 63 and slidable upon the tubular member I 0. The construction is such that by raising the projecting end of the member E until the apertures through which the tubular member I0 projects align themselves, the member E can be freely moved along the tube I0 but when a force is applied to the top of the projecting end of the member E, the platelike members 62 tend to pivot about the tube I0 and tightly engage the same. For a given movement of the lifting assembly A, the adjustability of the member E greatly extends the range of the jack.

From the foregoing disclosure of the present invention, it will be apparent that the objects heretofore enumerated and others have been accomplished and that there has been provided a simple and inexpensive hydraulic jack which is self-contained and Will not leak fluid. While two preferred embodiments of the invention have been described in considerable detail, the invention is not limited to the particular construction shown which may be varied in many respects without departing from the invention and it is my intention to hereby cover all adaptations, modifications and uses thereof which come within the practice of those skilled in the art to which the invention relates and within the scope of the appended claim.

Having thus described my invention, I claim:

A liquid pump comprising a member having an annular aperture therein closed at one end and annularly spaced inlet and outlet ports opening into said aperture adjacent to but spaced from said closed end, a piston rotatable in said aperture, Valving means associated with said piston for alternately connecting said ports with the portion of said aperture intermediate the closed end thereof and said piston upon rotation of said piston, and means comprising a cooperating cam groove and roller associated with said member and said piston for reciprocating said piston through a predetermined stroke upon rotation thereof, said cam groove having a recess or aperture in one side thereof permitting movement of said piston beyond said predetermined stroke and said piston having an aperture therein effective upon axial movement of said piston beyond said predetermined stroke for connecting said ports together.

MARION W. HUMPHREYS.

REFERENCES CITED The following references are of record in the le of this patent: i

UNITED STATES PATENTS FOREIGN PATENTS Country Date France 1936 Number Number 

